基于LMI的船舶力控减摇鳍系统H∞控制器设计

本文针对海浪伯随机干扰，船舶模型的不稳定性和控制器的输出约束，采用升力反馈控制的全新方法建立系统数学模型，用基于LMI（Linear Matrix Inequality)的H∞控制方法，考虑混合灵敏度S／KS问题，设计了H∞控制器，对混合灵敏度S／KS问题模型，权函数的选择等问题进行了研究，充分地利用了LMI法进行H∞设计时的优势，并对LMI法的优势进行了系统的说明和讨论，通过仿真验证了这一设计的可行性，所设计的力控减遥鳍系统不但具有抗干扰性能，而且具有鲁棒稳定性。     

Online channel strategies under different offline channel power structures for the Belt and Road of China

ABSTRACT

This paper explores the online channel strategies adopted by Chinese manufacturers with regard to the Belt and Road. It also investigates the effect of offline channel power structures and maritime transportation costs on online channel mode selection and pricing strategies. The offline channel power structures are classified into three types, namely, Chinese manufacturer Stackelberg (MS) structure, vertical Nash (VN) structure, and foreign retailer Stackelberg (RS) structure. Furthermore, a game model is developed among the Chinese manufacturer, foreign retailer, and cross-border e-tailer to investigate the interactions among offline channel power structures, maritime transportation costs, and Chinese manufacturers’ online channel mode selection. The results show that Chinese manufacturers’ preferences for the online agency selling mode increases correspondingly with the decrease in their market position and bargaining power. Moreover, foreign retailers can obtain higher profits in the online agency selling mode under the VN structure. However, the level of profit for foreign retailers depends on the intensity of their competition with cross-border e-tailers under the MS and RS structures. Finally, consumers in countries along the Belt and Road can obtain a higher surplus in the online agency selling mode under all of the structures.     

川江上游船型比选思路探讨

本文在分析川江上游运输船舶现状的基础上,提出船型比选的原则,并阐述了对现有船型比选的思路和方法,最后介绍了采用VB开发的计算机比选程序。     

变频器的谐波干扰与抗干扰

变频器通常由整流回路和逆变回路组成,变流回路因非线性特性而产生高次谐波。高次谐波的干扰影响电气设备的正常工作,应当采取必要的防范措施。     

Study of automatic designing of line heating technique parameters

1Introduction Lineheatingisashellplateheatprocessingmethod usedinshipbuildingproduction.Itisacomplexand difficulttechnique,mainlyusedindoublebending shellplateforming.Becausetherearemanyinfluence factorsinplateforming,theinfluencedisciplineis hardtopredic…     

舰船尾部改型的几种措施

介绍尾楔、尾压浪板、尾楔／板结合体、“鸭尾”和增加沉深等五种舰船尾部改型的措施，对国内外的研究以及应用情况进行总结。给出近期设计实践中增加沉深后的改型和原型试验的比较结果。对各种尾部改型的水动力机理进行描述。尾部改型可以起到减阻节能的作用，即可在设计的初步阶段考虑，它们的应用开阔了舰船附体设计的思路。     

船舶电力系统的电能质量问题

传统电能质量的监测和管理都是基于有效值基础之上,主要针对电力系统的稳定特征,缺少对暂态或瞬态过程的特征描述。本文旨在通过论述电能质量概念的提出及其基本发展现状,讨论现代舰船,特别是综合电力推进舰船面临的电能质量问题,分析解决舰船电能质量问题的基本措施。     

Fault Diagnosing System of Steam Generator for Nuclear Power Plant Based on Fuzzy Neural Networks

All kinds of reasons are analysed in theory and a fault repository combined with local expert experiences is establishedaccording to the structure and the operation characteristic of steam generator in this paper. At the same time, Kohonen algo-rithm is used for fault diagnoses system based on fuzzy neural networks. Fuzzy arithmetic is inducted into neural networks tosolve uncertain diagnosis induced by uncertain knowledge. According to its self-association in the course of default diagnosis. thesystem is provided with non-supervise, self-organizing, self-learning, and has strong cluster ability and fast cluster velocity.     

Tribon环境下船体分段拼板图自动设计方法研究

船体分段拼板图设计是船舶建造生产设计中的重要内容,目前主要依靠人工绘制,效率较低。基于Tribon的GEN文件对分段拼板图自动设计方法展开了研究,通过提取拼板图设计必需的图形信息并进行自动区域划分和定义,确定各类型数据间的相互逻辑关系。在此基础上,确定各类标注尺寸的自动计算方法,实现分段拼板图的自动设计,不仅能够提高拼板图设计的准确性,而且能够提高拼板图的设计效率。     

舰船电力系统保护性能优化的自适应算法

为满足舰船电力系统保护在快速性和选择性方面的要求,提出保护性能优化模型,根据电力系统的运行方式、拓扑结构和故障类型的变化,实时在线计算并修改保护整定值的自适应保护方法。将快速性和选择性指标作为保护性能综合指标的基本元素,采用模拟退火粒子群算法进行优化,最终实现不同运行工况下保护性能最优的整定值自适应调整。并在PSCAD/EMTDC软件中建立包含自适应保护算法的舰船电力系统保护仿真模型,仿真结果证明所提方法可有效提高系统保护性能。